Making metal castings



S. LAKE MAKING METAL CASTINGS Filed Jan. 1.5, 19.20

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3 Sheets-Sheet l IN1/ENQ 0R.

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mh 3L w25. l @53mm S. LAKE MAKING METAL CASTINGS Filed Jan. 13, 1920 3 Sheets-Sheet 2 INVENTOR. kf/

A TTORN E Y.

Marci 31, 1925. 1,531,445

INI/EN TOR.

A TTORNEY.

Patented Mar. 31, 1925.

UNITED STATES SIHON LAKE, OF MILFOBD, CONNECTICUT.

MAKING METAL CASTINGS.

Application led January 13, 1920. Serial No. 351,097.

To all/whom itmwy concern.'

Be it known that I, SIMON LAKE, a c1t1- zen of the United States, residing at M11- ford, in the county of New Haven and Stante of Connecticut, have invented a certain new and useful Improvement in Making Metal Castings, of which the following is a full, clear, and exact description.

This invention relates to the art of making metal castings, and is in the nature of an improvement on the invention set forth in my Patent No. 1,272,062, dated July 9, 1918, for apparatus for making metal cast- 1n s.

Ine object of the invention is to facilitate the casting of metals such, for example, as steel and aluminum which are subject to a marked degree to shrinkage when cooling, to the end that breaking of the casting is avoided.

Another object of the invention is to prevent uneven cooling or chilling of the casting in the mold, thus tending to produce a casting the metal of which is of a uniform texture throughout.

Still another object is to make possible case-hardening or annealing or other heattreating of the casting while still in the mold, thus combining the operations of casting and heat-treating in a single appar ratus.

A further object of the invention is to produce castings in such a manner as to reduce cooling shrinkage to a minimum, eliminate blow holes, and increase the tensile strength of the metal of the casting.

A still further object is the production of a ask the cope and drag of which are so held in proper relation to each other as to obviate the necessity for the usual attaching devices, the means for eiecting this also providing for hermetically sealing the ask.

Other objects and advantages will appear as the description of the invention proceeds. The invention consists in a method of and apparatus for roducing metal castings in which the metal) is cast under heat and Apressure in a mold formed in sections to provide for shrinkage during cooling of the casting, and provided with means for heating it, to the end that a casting of uniform density and tained, all as I will proceed now to explain and nally claim.

In the accompanying drawin illustrat# ing the invention, in the severa figures of texture throughout may be ob-` which like parts are similarl designated, Figure 1 is a sectional elevation, taken in the plane of line 1-1 of Fig. 2. Fi 2 is a plan view showing the flask and enc osin member. Fig. 3 is a transverse longitudina sectional elevation, showing in plan the drag of the flask with a core in place, on a larger scale. Fig. 4 is an enlarged vertical longitudinal sectional view of the flask and associated parts. Fig. 5 is a section taken in the plane of line 5--5, Fig. 3, omittin the enclosing member. Fig. 6 shows a mo ified form of apparatus.

The apparatus shown in Figs. 1 to 5 comprises a ask composed of a cope 1 and dra 2, suitable dowels 3 being provided to hol these parts in proper relation. The drag 2 has a bottom 4 also held in position by dowels 5. In use the drag, containing its half 6 of the moldis placed u on the base 7 of a hydraulic orl other suitable press, and the cone 1 with its half 8 of the mold is properly positioned upon it by means of the dowels 3. The ilask is then enclosed as to its sides and ends by meansy of a frame or casing 9 here shown as composed of channel members, and this frame is provided at top and bottom with compressible strips or gaskets 10 and 10 of rubber or other suitable material as shown.

The mold which I have devised, for the purpose of preventing fracture of the casting during cooling, and split laterally into halves 6 and 8, is formed of some permanent material such as cement combined with broken lire-brick, whereby a mold of the requisite porosity and strength to stand up through successive casting operations is provided, and this mold is also formed in sections as clearly shown in Fig. 2, with spaces 11 left between them whereby when the casting contracts while cooling the sections may be capable of relative movement to accommodate this contraction or shrinkage. Although I have shown the mold as divided into sections laterally only and in Aonly two places, it is obvious that it might be parted in as many planes and at as many oints as the nature and shape of the cast- 1ng to be formed would require. v

When the mold is bein set u the spaces 11 are filled with ne san 12 w ile the pattern is in place and when the pattern is removed the interior of thev mold may be painted or otherwise covered with a coating 13 of graphite, bone black, potash, lime or the like, or other coatings which under susin the usual manner, as by the four-wayy valve 16 to lower the head 17 over the ask and into contact with the packing strip or gasket 10 and sufficient pressure may be applied to compress this strip 10 and consequently also the strip 10 and the layer of sand 14 to thereby hcrmetically vseal the flask and its mold within the frame 9 and 'A the-base 7 and head 17 of the press, and

by compressing thel layer of sand, the mold is .effectively protected against fracture and its halves against separation when pressure is applied to its interior as will be Ylater described. Keys 18 and wedges 19 are used to vhold the frame 9 in proper relation to the base and headof the press, and in addition to this method of mounting the ask inf-the press furnishing a hermetic lseal it does away with the multiplicity of fastenin devices commonly used to hold the cope an dragr together.

4V.The bottom plate 4 of the drag is providediwith holes 20 in line with the openings 11` so that when the flask is removed from the'press, the sand may run out of the openings 11 'and thus admit of the sections of the mold having relative movement to ac-` i Akcommodate the shrinkage of the casting.

between the two.

v'Each rhalf of the mold is provided with Y wires 21 electrically connected at their ends with bars 22 provided with dowels 23 which in addition to acting as alining means for the moldhalves, act as electrical conductors `Tothe bar-r22 at oneyend of the mold is connected a cable 24 running to one termmal fof a source of electrical energy, and tothe i bar 22 at-the-other end of the mold is connected another cable 25 runnin to the opposite-terminal of the source of e ectrical energy, so that when current is turned on, the wires 21 through their connection with the bars 22, will be energized fand the resistance set up in them will heat the mold.

. If'themold is of a character thatl requires coring, as that shown in the drawings, the

c core,26 also may be provided with heating wires 27 so arranged that the core may be removed from the mold without destroying the electrical e' uipment thereof.

The head o the press is provided with openings 28 and 29 having bolt lianges 30,

y and these openings provide pouring and exhausting communication respectively with the interior ofthe mold, and the flan es 30 :are .adapted-to, receive the pouring an .pressure-applying mechanism, and the exhausting mechanism, shown and described in my patent above mentioned, or they may Vreceive the modified forms of these devices shown in Fig. 6 and hereinafter explained. It will of course be understood that a number of asks may be mounted in the same press for pouring at the same time, but for convenience of illustration, and in the interest of clearness, only one is so shown in the drawings.

Assuming that the flask with its Amold has been mounted :and hermetically sealed, as described, .and that the electrical connections'have been made, and the exhausting and pouring and pressure-applying mechanisms are in lace, the operation of forming a casting y my method is substantially as follows: The electric current is turned onv and the mold and core are heated to a high' temperature, then the exhausting apparatus is operated to exhaust a-ll air lfrom the mold cavity and to thereby produce a, vacuum therein. At the same time the heat will have thorou Vhl dried the mold so that no moisture wil be present to create vapor when the molten metal is introduced. The

Amold being dry and under a vacuum, the

a high temperature until the applied pres-l sure forces into the mold cavity. all the metal that it will contain, and densies this metal, thus homogenizingits texture, eleminating blow-holes, and increasing its tensile strengh, so that there is no hard outer. crust on the casting where it comes in contact with the mold, and no inner soft spongy core, as is now the fault in so many castings, but the whole casting is of the same texture throughout.

As above stated, it is also possible with my heated mold, to heat treat the casting in the mold, to harden, anneal or otherwise affect it, depending upon the composition of the dope or paint of the coating 13 with which the interior of the mold may be provided. I

When the casting operation isI completed the electric current is out od andthe press head raised, whereupon the flask with its mold may be transferred to a' cooling place. As before described, the sand in the openings 11 will run out and allow the sections of the mold to 'move relatively as the casting shrinks.

The greatshrinka e of castings of steel and aluminum and ot er hard metals, is due to their very porous nature which is probfil must be poured and the consequent great reduction in heat and volume as they cool, but with my apparatus, the use of pressure in filling the mold so densiies the metal of the casting as to reduce the chance for shrinkage to a minimum.

In Fig. 6 I have shown a modification of my invention, in Which the metal of the casting itself is used to conduct the electric current and is thereby consequently heated, thus obviating the necessity for the heating Wires in the mold, although the latter is my preferred form of apparatus.

In this modified -form I show an exhausting mechanism 31 bolted to the flange 30 of the opening 29, and comprising a tube 32 lined with a refractory non-conducting substance as at 33. In this tube is a hollow electrode 34, preferably of carbon, provided with a post 35 extending through a sealing plug 36 in a T 37, and to this post is connected an electrical conductor 3S. The electrode 34 is slidable in the tube 32 and can be moved toward and away from a disk 39 of porous conducting material such as carbon capable of allowing air to be sucked through it by a suitable pump piped to the T 37 as at 40 but impervious so far as the molten metal in the mold is concerned.

The other terminal of the electric circuit is connected to the plug 41 by means of a conductor 42.

It will thus be seen that current can be passed through the molten metal trapped in the mold cavity by the disk 39 and plug 41, by means of the plug 41 and electrode 34.

It is to be understood that I do not 'consider my invention as limited to the exact details of construction and arrangement here shown, nor to the precise mode of carrying out the method of casting therewith, as various changes maybe made Without departing from the spirit of the invention or the scope of the claims following.

l. In an apparatus for making metal castings, a flask, a mold Within said flask, va frame adapted to surround said flask and provided with sealing means adapted to be compressed to form a seal around said mold, means for creating a vacuum Within said mold, and means embedded in said mold for heating it.

2. In an apparatus for making metal castings, a flask, a mold formed of a hard, porous material capable of resisting pressure, independent means for hermetically sealing said mold within its flask, means for producing a vacuum within said mold, means for introducing molten metal into said mold and for applying pressure thereto, and means embedded in said mold for heating it'.

3. In an apparatus for making metal castings, a flask, a mold within said flask and composed of a permanent mold material, means surrounding said mold and-flask and adapted to hermetically seal the mold, heating means in said mold, means for exhausting air and gases from said mold, and metalintroducing and pressure-applying devices connected with the mold.

4. In an apparatus for castings, a flask, a mold formed in sections and adapted to be arranged vin said flask with its sections spaced apart. the spaces between said sections being filled with a pulverulent material, for the purpose specified.

5. In an apparatus for making castings, a mold formed in sections, said sections adapted to be spaced apart and the spaces filled with pnlvcrulent material during the castl ing operation, and means -for allowing the pnlvcrulent material to run out of said spaces whereby the spaces may he open during the cooling of the casting.

6. In an apparatus for making metal castings, a flask having a cope and a drag, means for holding the same in alinement, a sectional mold in said flask, spaces between the sections of said mold, a bottom to said drag. lilling material in said spaces, a covering of pnlvcrulent material on t-hc top of said mold, means for apply-ing pressure to hermctically seal said mold within a sealing means and for compressing said covering to maintain said mold in pressure-resisting Vcondition during the casting operation, and means in said bottom for permitting the escape of said filling material during the cooling of' the casting.

In testimony whereof I have hereunto set my hand this 12th day of January, A. D.

SIMON LAKE. Witnesses:

L. B. MCLAUGHLIN, ROBERT M. KEYS. 

